In the conventional high frequency apparatus, the inductance of tuning part of voltage controlled oscillator was formed with a strip type transmission line alone, for the sake of securing a high anti-vibration property.
Namely, if the inductance is formed with e.g. a coil component a vibration may cause vibration of wire of the coil, which invites a shift in the inductance value, resulting in a displacement of a tuned frequency. In order to avoid the occurrence of such phenomenon, the inductance was formed solely with a strip type transmission line.
A problem in the above described structure, where the inductance of tuning part is comprised of a strip type transmission line alone, is that fine tuning of tuning adjustment is not easy, because the dispersion due to component constant and mounting position of electronic components constituting local oscillator is compensated before completion.